Periodontal disease is a major public health problem which leads to loss of teeth and associated functional and social disabilities. There are some indications that periodontal health has improved in the American population, but no consistant data exists. The Amish are a unique isolated population within United States society and appear to have a low level of periodontal disease. The cause is unknown in spite of the fact that the Amish do not brush their teeth or visit dentists regularly based on two preliminary surveys conducted by our department. The specific aims are 1) to assess the prevalence and severity of periodontal disease among an Amish population, 2) to identify selected members of subgingival plaque flora using immunofluorescence microscope, 3) to culturally analyze selected plaque samples, 4) to enzymatically analyze selected plaque samples, 5) to assess dietary histories of Amish (samples), 6) to assess fasting blood levels of glucose, insulin, triglyceride, cholesterol and lipid lipoprotein subfractions, and 7) to relate dietary intakes to prevalence and severity of periodontal disease. The subjects will be a total of 450 adult Amish residing in Quincy, Branch County, Michigan. Data will be collected by 1) dental examinations, 2) plaque sample collection, 3) face to face interviews, and 3) drawing blood samples. Elementary statistical descriptors will suffice to assess the prevalence and severity of periodontal disease among the Amish. Non parametric descriptors and/or tests will be substituted for normal-based procedures when warranted.